my hub asked me this one and i told him this.
you know how you are just now recent surgery
how you are full after sipping (because you are swollen) and you feel (like you just cant eat).......that to me, as i see it, is restriction......i am probably wrong, but that is my opinion/view of your question.....it varies with each person though.
i am lucky i guess, i have had that feeling from day 1
because of my band/plication, i cant eat more than my allotted amount.....very uncomfy so i stop.